Silverhill Seeds, hardiness
J.E. Shields (Sat, 07 Feb 2004 08:33:58 PST)

Joe, Ken, and all,

Good points. I am most interested in the hardy and almost-hardy
bulbs. After all, I have a lot more space to grow things outdoors than I
do under glass and plastic.

Hardiness outdoors here in mid-zone 5 is very important to me. However,
zone 5 in Indiana is a wet zone, with almost 40 inches of precipitation (as
liquid) each year. We get at least 2 inches per month, and obviously we
often get more than that. The plants from arid and semi-arid climates are
more likely to suffer from the moisture here.

We cannot grow Kniphofia hirsuta, citrina, sarmentosa or stricta out in the
open. They seem to survive in protected spots outdoors, such as next to
the southeastern corner of one of the greenhouses. the stricta and the
citrina seem to bloom sometimes there too.

Kniphofia caulescens survived several years and bloomed once outdoors on
the south side of a very large Colorado Spruce tree.

Kniphofia northiae survived several years but never bloomed out in the wide
open spaces of a fully exposed, raised rock garden bed.

I have not tried the K. uvariae hybrids yet. I planted some K.
linearifolia outdoors in a raised sandy bed, but I don't think they
survived. I'll check again next season to be sure.

Other unexpectedly hardy South African bulbs here are Crinum variabile as
well as CC. bulbispermum and x-powellii, and [bulbispermum X
lugardiae]; Gladiolus oppositiflorus salmoneus (but this depends greatly
on the specific site) while G. dalenii has not survived. Dierama
dracomontanum and latifolium survived outdoors in the ground for several
years in a reactively dry bed. Morea galpinii has done better than other
Morea outdoors here, but it is not able to bloom.

Zantedeschia have not survived outdoors in the open ground
here. Nevertheless, I keep trying and hoping. I have one large plant of
Z. aethiopica 'Green Goddess' planted up against the outside of the south
wall of one greenhouse, between a couple of surviving crinums. Maybe it
too will survive....... I had numerous seedling pots of Zantedeschia
seedlings that had survived two winters in a cold frame die last winter in
the same cold frames. It was unusually wet last winter, and the
temperatures stayed below freezing for long periods without any
thawing. Too cold and too wet apparently did them in.

I'm always looking for more potentially hardy bulbs to test here. Do you
have any you would like me to try here? There is lots of room out in the
nursery beds.

Best wishes,
Jim Shields
in central Indiana (USA) where our coldest temperature so far this winter
was -8 F (about -22 C)

*************************************************
Jim Shields USDA Zone 5 Shields Gardens, Ltd.
P.O. Box 92 WWW: http://www.shieldsgardens.com/
Westfield, Indiana 46074, USA
Tel. ++1-317-867-3344 or toll-free 1-866-449-3344 in USA